Civil 3D Tip: Creating Offset Alignments and Profiles in Civil 3D
It’s easy to create offset Alignments and Profiles in Civil 3D. In fact, you can do both within the same command. In this example, we have an alignment with a profile that represents the centerline of a road. We want to create Alignments with Profiles, representing the left and right sides of the roadway at the edge of pavement. We want to ensure that they are dynamically tied to the centerline so that any changes we make to the centerline are reflected on either side of our roadway.
Start by selecting the centerline, also referred to as the parent alignment. Then in the contextual ribbon, select “Offset Alignment” as shown below:
This will open the “Create Offset Alignments” dialog box. Here you can create alignments to one or both sides, each at their own distance. Note: You may choose to create multiple offset alignments to either side, if desired. Distances and cross slopes can be edited at a later time.
You must first select the Alignment you are looking to create offsets from and set the station range you wish to create the new Alignments to. In this case, we are running the full length. Next, you will want to check the boxes of the side or sides you are creating to, as well as specify the number of offsets you wish to create to either side.
Under the General tab, set the Alignment Style. Next, set the layer you want the offset alignments to be placed on. You can also choose the label set at this time. Site input is not needed, but can be set if utilized.
Selecting the icon next to “Alignment Layer” will open the Object Layer dialog box.
There is an option to create offset profiles that are dynamic to the parent alignment’s profile, but it must be done at this time. To do so, you must check the box “Create Profile for Offset Alignment” located under the “Create Offset Profile” tab.
This will create profiles that are dynamic to your centerline profile at a specified cross slope. One profile will be created for each offset alignment created, but only at the specified cross slope. The user may adjust the cross slope value for profiles individually at a later time. You may choose to add these profiles to an existing profile view, if desired.
If you select the icon next to “Profile Name” it will open the profile naming template. Here, you can set automated naming conventions to add information such as Alignment Name, Offset distance, numerical counter (with specified Incremental number format), as well as profile type to the names of the profiles you are creating in this process.
Once profile style is set, click Ok to complete the command. Dynamic Offset Alignments and Profiles are now created.
The Offset alignments and profiles will now be available for individual editing in your Prospector.
Once created, Offsets can be edited within the “Offset parameters” tab in the Alignment Properties Dialog box. Note: the Alignments and Profiles will remain dynamic to the parent, unless disabled here. Once the dynamic tie for an offset alignment is broken, it cannot be restored. The alignment will remain categorized as offset alignment, however, any changes to the parent will not affect the offsets.
Cross slopes can be edited similarly within the Profile Properties, “Offset Parameters” tab.
